Anomale Oberflächenzusammensetzung stöchiometrischer Mischoxid‐Verbindungen

Abstract

Oberflächen-Oxidschichten kommen in vielen oxidhaltigen Materialien vor, z. B. als Korngrenzen in Keramiken [1] und als Grenzschichten in Keramik-Keramik- [2] oder Metall-OxidSystemen, [3] und beeinflussen deren Material-und Transporteigenschaften. In der heterogenen Katalyse sind die Eigenschaften der äußersten Atomschicht von herausragender Bedeutung, weil sie das katalytische Verhalten steuern.Obwohl Mischoxid-Vollkatalysatoren weithin in industriellen Selektivoxidationsprozessen eingesetzt werden, [4,5]

Tuning Surface Properties and Catalytic Performances of Pt–Ru Bimetallic Nanoparticles by Thermal Treatment

“…Owing to the neutralization of ions when penetrating below the surface, exclusive information on the outermost surface layer can be obtained by lowenergy ion scattering (LEIS). [14] Thus, we further studied the evolution of the surface composition of Pt-Ru/C, during thermal treatment, by LEIS. The LEIS results for Pt-Ru nanoparticles treated under various temperatures are shown in Figure 1.…”

Tuning catalysis by surface-deposition of elements on oxidation catalysts via atomic layer deposition

“…As a result, in particular the interplay between the bulk and the dynamic surface of a bulk catalyst seems to be the key for high performance in selective oxidation reactions. 41,42,109…”

“…40 Hence, the catalytic functionality of bulk catalysts is determined by the properties of the termination layer, which depends on the bulk composition and is formed under reaction conditions. 24,26,36,[41][42][43] However, the surface can additionally be modified using synthetic methods like atomic layer deposition (ALD). The deposition of elements via volatile precursors using self-limiting surface reactions during ALD is utilized to tune the properties of the catalyst precursor at the atomic level.…”

Humboldt‐ und Bessel‐Forschungspreise, Camille Dreyfus Teacher‐Scholar Awards

“…Zurzeit ist er G. Whitney Snyder Professor und Professor für Chemieingenieurwesen an der Lehigh University, Philadelphia. Er nutzt in seiner Forschung die optische Spektroskopie, um die Eigenschaften von Oberflächenoxiden zu untersuchen 8 …”